Hi everyone,

I drive a Škoda Octavia Mk3 and have generally been quite happy with the factory audio system – it's not high-end, but it delivers decent sound for everyday use.

Recently, however, my front door speakers started failing. The left one crackles badly, and on the right side, only the tweeter still works. No idea how it happened – maybe the kids played something too loud...

Now I’m considering replacing the OEM speakers with something like these:
🔗 Hertz Uno K 165 – 300W Component Speakers

On paper, they look good: 93.5 dB sensitivity, decent power handling, and Hertz is generally a respected brand.

My question is:
Would these offer a noticeable improvement over the factory speakers?

Or would it make more sense to simply source used OEM replacements? The originals have basic paper cones and small neodymium magnets – they look underwhelming, but surprisingly, they sound pretty good, with decent bass response too.

Has anyone here replaced the stock speakers in a newer Octavia (Mk3 or Mk4)?
I'd really appreciate any feedback or recommendations based on your experience.

Thanks in advance!

I did some research on this topic — the Russians are the best at it, especially on the drive2.ru forum.

Newer Octavia 3 models mostly have speakers with the part number 5E0035411J. They have a large magnet compared to older series and sound good. However, they have an issue with the magnet shifting or coming off. When the magnet moves slightly, it presses against the voice coil, and the speaker can no longer play, or the coil scrapes against the magnet, producing a crackling noise. This seems to be a common problem with this speaker series. If the magnet shifts or falls off, a special centering tool is required to realign it. It can be fixed, but it’s difficult.

I didn’t want to buy aftermarket speakers (Hertz, Pioneer, Ground Zero, etc.) because I believe that the cheaper series without an amplifier wouldn’t sound any better, and I’d have a hard time with installation, spacers, adapters, and so on.

I ordered a used pair of 5E0035411J speakers for my Škoda, €40 per pair. I applied Bison two-component epoxy adhesive around the magnet, and I hope it can no longer shift.

The sound is back to its usual good quality — there’s a nice amount of bass, nothing premium, but perfectly satisfactory for a car

On 01/08/2025 at 07:16, remark78 said:

Hi everyone,

I drive a Škoda Octavia Mk3 and have generally been quite happy with the factory audio system – it's not high-end, but it delivers decent sound for everyday use.

Recently, however, my front door speakers started failing. The left one crackles badly, and on the right side, only the tweeter still works. No idea how it happened – maybe the kids played something too loud...

Now I’m considering replacing the OEM speakers with something like these:
🔗 Hertz Uno K 165 – 300W Component Speakers

On paper, they look good: 93.5 dB sensitivity, decent power handling, and Hertz is generally a respected brand.

My question is:
Would these offer a noticeable improvement over the factory speakers?

Or would it make more sense to simply source used OEM replacements? The originals have basic paper cones and small neodymium magnets – they look underwhelming, but surprisingly, they sound pretty good, with decent bass response too.

Has anyone here replaced the stock speakers in a newer Octavia (Mk3 or Mk4)?
I'd really appreciate any feedback or recommendations based on your experience.

Thanks in advance!

They are absolutely better speakers than stock, and by a vast margin, but those Hertz want 75w RMS. They'll be massively underpowered by the stock headunit, which probably puts out something like 25w RMS. You'll struggle to get them to sound good. Ideally, you'd need to amplify them - but that opens a whole can of worms!

I've just replaced all the speakers in mine with Alpine S2-S65Cs. Coincidentally, I tried those Hertz first, but was underwhelmed; they really lack bass. I got the Alpine instead, and I'm much happier. The Unos will be getting sold. I've replaced my headunit and added amplifiers, so I'm quite a way from standard.

i have full hertz system in my fabia combi. 165 midway dot front. tweeter near mirror 165 full tone back. 2x hertz mps300 s2 in the back and 2 x heartz mono blok 1000 rms each. and match pp62d dsp with build in amp also for front. its sound amazing. all is hertz pro series.

u have to drill the speakers out and buy adaptors to new speakers and a an adaptor to wire for vw.

@hill79 which headunit do u have now then ?

Edited 8 October, 20258 Oct by duckkicked
Pictures

12 minutes ago, duckkicked said:

i have full hertz system in my fabia combi. 165 midway dot front. tweeter near mirror 165 full tone back. 2x hertz mps300 s2 in the back and 2 x heartz mono blok 1000 rms each. and match pp62d dsp with build in amp also for front. its sound amazing. all is hertz pro series.

u have to drill the speakers out and buy adaptors to new speakers and a an adaptor to wire for vw.

@hill79 which headunit do u have now then ?

That looks really nice! Hertz pro stuff is good, I think they cut corners for the Uno range though.

I've got a JVC m745dbt, I've had it a good few years and it's come with me through several cars now. I love the fact it's a shallow profile so there's always loads of room behind to get the wiring tidy. I've got a Vibe powerbox with a built in DSP running the front speakers and a Audio Control Epic 1000 running two 12s in the boot.

Still working my way through tuning it properly with REW, and I need to line the boot with deadmat when the weather improves, but I'm getting there!

26 minutes ago, hill79 said:

That looks really nice! Hertz pro stuff is good, I think they cut corners for the Uno range though.

I've got a JVC m745dbt, I've had it a good few years and it's come with me through several cars now. I love the fact it's a shallow profile so there's always loads of room behind to get the wiring tidy. I've got a Vibe powerbox with a built in DSP running the front speakers and a Audio Control Epic 1000 running two 12s in the boot.

Still working my way through tuning it properly with REW, and I need to line the boot with deadmat when the weather improves, but I'm getting there!

Nice setup too! Vibe is a power monster! I have switch the original battery to a 90 amp and then bridge in the back and 100 amp more.

It’s hard to find a headunit that matches the size instead of admunsen mib2.

My future plans is those midways 70.3 and more sound isolation.

Back seat is my trunk! Nothing allowed in the real trunk because of all that electronic

Edited 8 October, 20258 Oct by duckkicked